Fix MIT license specification

debian/copyright

@@ -12,7 +12,7 @@ License: LGPL-2.1
 Files: src/collapsiblepane.*
        src/dialogabout.*
 Copyright: 2021-2023 Andrea Zanellato <redtid3@gmail.com>
-License: MIT
+License: MIT (Expat)
 
 Files: resources/freedesktop/application.appdata.xml.in
 Copyright: none
@@ -36,7 +36,7 @@ Comment: Per the COPYING file: The exception in section 5 of the GNU Lesser
 
 Files: debian/*
 Copyright: 2023 Simon Quigley <tsimonq2@ubuntu.com>
-License: MIT
+License: MIT (Expat)
 
 License: LGPL-2.1
  This program or library is free software; you can redistribute it
@@ -53,7 +53,7 @@ License: LGPL-2.1
  Public License version 2.1 can be found in
  "/usr/share/common-licenses/LGPL-2.1".
 
-License: MIT
+License: MIT (Expat)
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights